Or is it?
"In reality, the day before Thanksgiving is not the busiest day of the year," said Roger Dow of the U.S. Travel Association.
In fact, according to official government data, when it comes to the number of airline flights, today doesn't even rank among the top 25 busiest days.
Back in 2006, it came in 36th. In 2007, it was 55th. And last year, as the economy took a turn for the worst, there were 220 days with more flights than the day before Thanksgiving.
"It's a myth," Dow said. "lt's one of those things that people expect the airports to be crazy - there's a lot of people traveling, but it's not the worst day of the year."
So if it isn't the busiest travel day of the year, what is? The day before Christmas, perhaps? Maybe the day before Memorial Day weekend?
Dow says it's simple. The busiest travel days of the year are, "Fridays, June, July and August."
That's right. Last year, the No. 1 day was Friday July 18 -- the day before, well, Saturday. There were 21,128 flights that day - 2,273 more than on the day before Thanksgiving.
Consider this: AAA estimates that 2.3 million Americans will fly this holiday weekend -- that's a 62 percent drop from the 6.2 million who flew nine years ago.
But more than 33 million will drive - which means, as usual, the worst congestion will be on the road, not in the skies.